Spotted Blue-eye - Pseudomugil gertrudae

The Spotted Blue-eye was scientifically described by Weber in 1911. Its scientific name is Pseudomugil gertrudae. The species was first collected by Dutchmen at the Aru Islands of eastern Indonesia in the early 1900s.

Description
The Spotted Blue-eye can reach a length of 3.8 cm (1 ½ inches). The body is whitish and is decorated with an intricate pattern formed by narrow, dark scale outlines. In some specimen, the whitish colour is has a golden lustre. The dorsal, anal and caudal fins of the Spotted Blue-eye are all yellow and adorned with small black dots.

In adult males, the middle rays of the first dorsal fin and the anterior rays of the pelvic fins are elongated.

Geographical distribution, habitat and conservation
The Spotted Blue-eye can be found in northern Australia and southern New Guinea. The Australian population consists of several isolated groups.

The Spotted Blue-eye is inhabits several different habitats and can be found in open sand-soil landscapes as well as in densely shaded rainforest streams. It lives in streams, creeks, swamps, marshes and lily lagoons, and can also be found in the slow-flowing backwaters and overflows of major rivers. The bottom is usually muddy and the water clear, but some Spotted Blue-eye populations live in turbid waters or are used to an environment filled with suspended green algae. The pH-value of these habitats varies from 5.2 to 6.7.

The Spotted Blue-eye has not been evaluated for the IUCN Red List of Threatened Species. In Australia, land clearing for farming purposes has led to habitat loss.

Keeping Spotted Blue-eye in aquariums
Even a small 20 litre (5 gallon) aquarium is large enough to house Spotted Blue-eyes, provided that you know how to keep the water quality up in such a small aquarium. Since this is a very small and peaceful fish, it can only be combined with other small and really peaceful species. It is commonly kept in species aquariums.

The Spotted Blue-eye is known to congregate around sunken trees and in densely grown areas in the wild and you should therefore strive to create a similar environment in the aquarium using drift wood and plants. Floating plants are appreciated.

The Spotted Blue-eye is an adaptable fish that can tolerate a pH-value from 3.8 to 7.8, but keeping the water close to pH 6.0 is recommended. The water temperature should be 23-30 degrees C (73-86 degrees F) in the aquarium.

Breeding Spotted Blue-eye
The Spotted Blue-eye is not difficult to breed in aquariums. Acidic water (down to pH 5.5) is known to increase the chances of spawning, but this species have spawned in alkaline aquariums as well. In addition to providing your fish with a suitable environment, it is important to give it live or at least frozen meaty foods, preferably combined with high-quality dry food. You can for instance cultivate brine shrimp and insect larvae at home.

The Spotted Blue-eye is normally bred in groups consisting of 10-20 fishes. There should be at least three females per male fish. Three males will for instance require at least nine females, since the males will chase the females quite relentlessly during the courting period. The more females the better, since this will disperse the amount of stress over more individuals. In addition to chasing the females, the males will keep erecting their dorsal and anal fins to show off during the courting period.

The Spotted Blue-eyes need a suitable spawning medium, such as densely grown java moss or spawning mops. They seem to prefer placing their eggs within 10 cm from the bottom, so make sure that the spawning medium reaches low enough in the aquarium.

The female Spotted Blue-eye will only release a small amount of eggs each day, typically fewer than 10 and she will not release more than three eggs at a time. If the aquarium is densely planted with plenty of hiding spots, at least a few fry will normally avoid predation. If you want a higher survival rate, move the adult fish or place the spawning medium with the eggs in a separate container. If you keep the water temperature in the upper part of the recommended range, you can expect the eggs to hatch within 12 days. The fry can be fed infusoria and finely powdered flake food until they are large enough to eat newly hatched brine shrimp and whole flake food.